Dust-cap for valve-stems



H. E. BLOOM.

DUST CAP FOR VALVE STEMS. APPLICATION mn MAY 20, I919.

Patented Feb, 10, 1920.

ROBERT E. BLOOM, OF BROOKLYN, NEW YORK.

DUST-CAP non VALVE-swans.

Specification of Iietters Patent.

Patented Feb. 10, 1920.

Application filed May 20, 1919. Serial No. 298,352.

To all whom it may concern:

Be it known that I, ROBERT E. BLOOM, of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Dust-Caps for Valve-Stems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to dust caps for valve stems of pneumatic tires, being particularly adapted for use in connection with automobile tires, and the object of the invention is to provide a simple cap for this purpose embodying improved means for retaining the cap on the valve stem and which will permit a quick placing or removal of the cap without the necessity of laboriously turning the cap as where screw threaded engagement is had between the parts.

In the drawing, Figure 1 is a vertical sectional view showing my improved cap applied to the valve stem. Fig. 2 is a View in perspective showing the clamping elements detached from the cap.

The valve stem A which is of known form with screw threads extending throughout its length projects inwardly throughan open ing in the wheel rim and is made fast to the rim by a nut B.

My improved cap 1 is of tubular form, closed at its upper end, and at a point adjacent its lower end is bulged, as at 2, a part of this bulged portion being cut away to form an opening 3 for a clamp which comprises complementary levers l and 5 extending transversely of the cap. Each of these levers is formed of a flat piece of metal with angularly disposed ears 6 b which it is pivotally secured to the bulge portion 2 of the cap, at a point removed from the longitudinal center of the cap, through the instrumentality of a pin 7 the pin forming a bearing for a coiled spring 8 adapted to exert tension on the levers.

That portion of each lever wholly within the bulged part 2 of the cap is ring-like in form, the opening being of a diameter slightly larger than that of the valve stem so that in one position of the lever it will freely pass over the threads of the stem while in its opposite position it will engage the screw threads and prevent the cap from being jostled or otherwise removed from the stem. The two levers are in spaced relation like portions toward each other and into engagement with the threads. In applying or removing the cap the outer ends of the levers are pressed so that the inner ends will practically be in parallelism and free to slip over the threads. Too great compression would cause the inner ends of the levers to pass beyond a point where the cap could readily be slipped off the stem, and to prevent any chance of this I provide the lever 5 with a stop 9 which is formed by bending the end of the lever upwardly so that it will lie directl under the end of the lever 4 and when bot are compressed they cannot move beyond the point which will allow the inner ends to freely slide over the valve stem.

To insure against the cap vibrating relatively to the stem I provide rubber askets l2 and 13 fitted, respectively, near the top and bottom of the cap, the gasket 12 having a small orifice to receive the small valve cap while the gasket 13 must be of suflicient size to permit passage of the valve stem. It will be noticed that any pull on the cap, without first compressing the outer ends of the levers, will have a tendency to make the levers bite the screws of the stem with greater force.

I claim as my invention:

1. In combination with a valve stem having an external thread, a dust cap of tubular form having a circumferential bulged portion terminating in an opening at one side, and includingclamping means secured to said cap, said clamping means having a portion fitting within the bulged part of the cap and adapted to encircle and engage the threaded stem.

2. In combination with a valve stem having an external thread, a dust cap of tubular form having an opening at one side, and including spaced apart clamping levers pivoted to said cap, said levers each having a portion extending through said opening and into engagement, with said threaded stem, and a spring for forcing the thread engaging ends of said levers toward each other.

3. In combination with a valve stem having an external thread, a dust cap of tubular form having-an opening at one side, and including spaced apart clamping levers fitted to said cap, each of said levers having a ring-like portion adapted to surround the Valve stem, and a spring normally tending to force the ring-like portions of said levers into engagement with the threads of said stem to lock the cap thereto.

4. In combination with a valve stem having an external thread, a dust cap of tubular form having an opening at one side,

and including spaced apart clamping levers fitted to said cap, each of said levers having a ring-like portion adapted to surround the Valve stem, and 'a spring normally tending to force the ring-like portions of said levers toward each other and into engagement With the threads of said stem to lock the cap thereto, and a stop carried by one of said levers to limit movement of said levers against the tension of said spring.

In testimony whereof I have signed this specification.

ROBERT E. BLOOM. 

